1. Field of the Invention
The invention is related to the field of electro-optic controls and in particular to an electro-optical control having at least two output switches activated in response to a received light signal being within or outside programmed limits.
2. Prior Art
Electro-optical controls for detection of objects, making measurements, or controlling a manufacturing process are well known in the art. Typical of a commercially available electro-optical sensor is the XSUNX sensor, manufactured by RAMCO Electronics of West Des Moines, Iowa, and the Smarteye photo electric sensor, manufactured by Tri-tronics Co., Incorporated of Tampa, Fla. The XSUNX sensor has four sensitivity levels selected by external signals, but does not have capabilities of displaying the detected signal level nor a keypad for entering limits or instructions to the sensor.
The Smarteye photoelectric sensor uses a pulse modulated light beam and has a contrast indicator which gives a scaled reading of the received light. This contrast indicator is a series of 10 indicator lamps labeled from 1 to 10. The Smarteye switches output when the light level passes the midscale contrast level 5. This sensor also has an OFFSET control which offsets the signal so that the output switches when the indicator lamp 5 is activated.
With present advances in manufacturing, there is need for an electro-optical sensor having greater versatility, having various functions that are programmable, and having a keypad which permits in situ programming of the electro-optical control.